Purpose: Recent studies of food allergy (FA) at all ages are scanty in Korea. We performed this study to better understand severityrelated and age-stratified causes of FA from infants to older adults in a single tertiary hospital in Korea. Methods: A retrospective medical record review was performed on patients of all ages diagnosed with immediate-type FA between March 2008 and February 2018 in Ajou University Hospital. Results: A total of 4,680 cases of FA among 2,733 patients were reported. The distribution of onset ages of the first FA symptom was as follows: 45.3% below 2 years, 16.2% at 2-6 years, 5.5% at 7-12 years, 4.0% at 13-18 years, 16.9% at 19-40 years, 10.4% at 41-65 years, and 1.8% above 65 years of age. The major 10 causative foods were hen's eggs (17.2%), cow's milk (16.7%), wheat (8.6%), crustaceans (8.5%), fish (4.6%), walnuts (4.4%), pork (3.2%), peanuts (3.2%), shellfish (3.0%), and peach (2.2%). The culprits ranked from the 11th to the 20th were as follows: soybean, apple, chicken, buckwheat, beef, kiwi, almonds, perilla seeds, tomato, and squid. The top 3 causative foods in children were hen's eggs, cow's milk, and wheat, while those in adults were crustaceans, wheat, and fish. Food-induced anaphylaxis was reported in 29.2% of all cases, with cow's milk, hen's eggs, wheat, crustaceans, fish, walnuts, pork, shellfish, buckwheat, and peanuts being the major 10 causes. Conclusion: This study could provide a better understanding of the detailed ranks of the causes of FA according to severity and age in Korea.
